Tool-retainer for hammer-drills



R. H. WILHELM.

TOOL RETAINER FOR HAMMER DRILLS.

APPLICATION FILED JUNE I6. 1919.

I I I I J I I I 11 I H I I||| III I I ATTORNEY RUSSELL H. WILHELM, OF EASTON, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

TOOL-RETAINER FOR HAMMER-DRILLS.

Specification of Letters Patent. Patented Apr. 19, 1921.

Application filed June 16, 1919. Serial No. 304,569.

To all whom it may concern:

Be it known that I, RUSSELL H. WILHELM, a citizen of the United States, residing at Easton, in the county of Northampton and State of Pennsylvania, have invented a certain new and useful Improvement in Tool- Retainer'sfdFHammer-Drills, of which the following is a specification.

This invention relates to a tool retainer adapted to be applied to the forward end of a rock drill or other percussive tool to partly surround the drill steel in advance of a collar usually provided on the drill steel so that when the percussive tool is raised or withdrawn from the hole being drilled, the drill steel may be withdrawn therewith.

The objects of the present invention are to provide a tool retainer of the class above described which'will be compact, strong, durable and not readily put out of order when in operation, and which may be readily moved from operative to non-operative position. 5 s..

A further object of the present invention is to provide a tool retainer which will be independent of the side rods and side springs with which the parts of the percussive tool are held together.

With these and other objects in view my invention consists in the features of construction and operationset forth in the following specification.

In the drawings annexed hereto *and forming a part hereof: I

Figure 1 shows a longitudinal side 'view, some of the parts being shown in cross section;

Fig. 2 a front end view with the retainer in operative position;

Fig. 3 a top view of the front end of tool with the retainer in operative position.

Fig. 4 a longitudinal outside view of front end of the tool and retainer.

Referring more particularly to the figures of the drawings, 1 refers to a percussive tool of any usual or common type, the one shown being of the hammer type of hand held tool for which the present invention is particularly adapted. The side rods usually found in this type of tool to hold the parts together, are shown at 2, and have compressive springs 3 mounted thereon, in advance rods 2 being provided with nuts 5 by means of which the pressure of springs 3 may be regulated. At 6 are shown lugs preferably formed integrally on the part of the drill in advance of the collar 4, this forward portion of the tool beingshown generally at 7, and forming the front head. Lugs 6 are located on opposite sides of the front head in a plane parallel to the central axis of'the tool but preferably lying as shown atone side of said axis. In Figs. 1 and 2 the lugs 6 lie below the said axis, which is the preferable construction. The lugs 6 are conveniently placed at a distance from the side rods so that there is no interference between.

the parts of the retainer and the side rods 2 and springs 3/ Passing longitudinally through the lugs 6 are holes 8 counterbored at their forward end for a considerable distance as shown at 9, and extending through these holes are eye bolts 10, the forward end being formed in an eye as shown in 11, and the rear end being threaded and provided with a nut 12. Between the rear of the lug 6 and the nut 12 is provided a sprin 13 of considerable strength or resiliency an within counterbore 9 of the lug 6 is provided a scplring 14 of lighter wire and less resiliency.

osing the forward end of tli'eeounterbore The one shown for the purpose of illustration being cast or forged in the form shown, but it is obvious that any convenient or usual form of steel retainer yoke may be utilized. The retainer 16 at its forward end is provided with the yoke portion 17 adapting separated when the retainer is in operative position. The rear. ends of the side arms of the retainer yoke 16 are formed as a double yoke shown clearly in Fig. 3 at 20 the parts of the double yoke being spaced widely enough to permit the eye 11 of the bolt 10 to pass between its two parts. These parts 20 are provided with holes extending transversely as shown at 21, permitting pins 22 .to be insertedwithin the yoke 20 and the eye 1.1 of bolt 10, thus permitting the steel retainer to be turned about the pins 22 from another necessitates the compression of springs 13 and 14. It will also be seen from Fig. 1 that when the retainer 16 has been moved to oneor the other of its positions,

it will be retained in that position by the collar 15 pressing a ainst the flattened rear surface 23 of the yo e 16. If the collar 19 strikes the portion 17 of the steel retainer, the resulting forces tend to force the portion 17 more firmly around the steel, instead of throwing it out of engagement with the col lar, due to the fact that the steel retainer is pivoted at points offset from the axis of the tool on the side opposite to that on which it can swing. R V

In operation considerable stress is freuently placed upon the steel retainer 16 by t e workman when removing the drill steel 18 from the hole or when the piston strikes the end of the drill steel and throws it forwardly very violentl For this reason the spring 13 is made su ciently strong to overcome these stresses. It is obvious, however, that it would require considerable force to remove the steel retainer from its operative to its inoperative position a ainst a spring of this strength and for t is reason the spring 14 is made much lighter, requiring a less force to compress it sufiiciently to move the tool retainer from one position to the other. e

To assemble the parts of the tool retainer, the pins 22 are placed in position extending through the eye 11 of bolts 10 and the yoke members 20 and then the bolts 10 with the collars 15 and springs 14 mounted on them are placed in the lu s" 6. The spring 13 isthen placed on the olt 10 and finally the nuts 12 on either bolt are. adjusted to give the right amountof resiliency to withstand the shocks to which the retainer is subjected and also to allow movement of the retainer from operative to inoperative position.

Having thus described my invention, what I claim is:

1. In a tool retainer for percussive'tools, the combination of a front head having a plurality of counterbores, bolts in said counterbores, compression springs surrounding said bolts between the bases of said counterbores and the rear ends of the bolts for yieldingly resisting forward movement of the'bolts, a steel retainer pivotally secured to the forward ends of the bolts, collars surrounding the bolts at the forward ends and adapted to bear on flat portions at the ends of the steel retainer and compression springs surrounding said bolts between the before mentioned ends of the counterbore and said collars for continuously exerting pressure to force the collars against said flat portions of the retainer and maintain the retainer in open or closed position.

2. In a tool retainer for percussive drills, the combination of a front head having oppositely projectin lugs, bolts passing longitudinally throug said lugs, compression springs surrounding said bolts between the lugs and the rear ends of the bolts for yieldingly resisting forward movement of the bolts, a steel retainer pivotally connected to the forward ends of the bolts, collars surrounding the bolts at the forward ends and adapted to bear on flat portions at the ends of the steel retainer, and compression springs surrounding said bolts between the lugs and the said collars for continuously exerting pressure to force the collars against said flat portions of the retainer and maintain the retainer in open or closed position.

3. In a tool retainer'for percussive tools, the combination of a front head having a plurality of counterbores, bolts in said counterbores, compression springs surrounding said bolts for yieldingly resisting forward movement of the bolts, a steel retainer pivotally secured to the forward ends of the bolts, collars surrounding the bolts at the forward ends and adapted to bear on flat portions at the ends of the steel retainer and compression springs engaging the ends of the counterbores and bearing against said collars for continuously exerting pressure to force the collars against said fiat portions of the retainer and maintain the retainer in open or closed position.

In testimony whereof, I have hereunto set m hand.

y RUSSELL H. WILHELM. 

